BACKGROUND: Mechanical insufflation-exsufflation (MI-E) and manually assisted cough are frequently employed cough augmentation methods for enhancing cough efficiency in individuals with cervical spinal cord injury (CSCI). This study aimed to evaluate the synergistic impact of combining manually assisted cough and MI-E on cough peak flow in subjects with CSCI and identify their related factors.
METHODS: Fifteen subjects with CSCI with cough peak flow > -270 L/min underwent 5 consecutive days of 5 cough augmentation sessions; cough peak flow during exsufflation and the total insufflation volume (TIV) during insufflation were measured. Only MI-E was administered on days 1 and 5, whereas on days 2-4 one MI-E-only session followed by 3 MI-E and manually assisted cough sessions was implemented followed by a fifth MI-E-only session. The cumulative and carry-over effects of increasing treatment sessions and any associated factor on cough peak flow during MI-E-assisted coughing were assessed using a linear mixed model (LMM) with repetitive air-flow measurements within the same participants.
RESULTS: No cumulative or carry-over effects of manually assisted cough and MI-E were shown with the accumulation of treatment days or sessions. The LMM confirmed that using manually assisted cough (-0.283 L/s, P < .001), TIV (-0.045 L/s, P = .002), and the individual manually assisted cough variance (-0.022 L/s, P = .01) significantly influenced cough peak flow. Estimated mean cough peak flows for MI-E with manually assisted cough and MI-E alone were -4.006 L/s (95% CI -4.237 to -3.775) and -3.723 L/s (95% CI -3.953 to -3.492), respectively, surpassing the initial voluntary cough peak flow without MI-E assistance (-1.65 ± 0.53 L/s).
CONCLUSIONS: The use of manually assisted cough and amount of TIV correlated with improved cough peak flow, emphasizing the importance of adequate in-expiratory support. No carry-over effect was associated with using manually assisted cough, highlighting the need to combine MI-E with manually assisted cough for each MI-E treatment to achieve optimal cough effectiveness.

BACKGROUND: Dyspnea is an unpleasant subjective symptom and is associated with decreased physical activity level (PAL). Effect of blowing air toward the face has received a great deal of attention as a symptomatic therapy for dyspnea. However, little is known about the duration of its effect and its impact on PAL. Therefore, this study aimed to measure dyspnea severity and changes in dyspnea and PALs with air blasts to the face.
METHODS: The trial conducted was open-label, randomized, and controlled. This study included out-patients with dyspnea caused by chronic respiratory deficiency. Subjects were provided a small fan and instructed to blow air toward their faces either twice a day or when having trouble breathing. Subsequently, severity of dyspnea and PALs was measured using visual analog scale and physical activity scale for the elderly (PASE), respectively, before and after 3-week treatment. Amounts of changes in dyspnea and PALs before and after treatment were compared using analysis of covariance.
RESULTS: Overall, 36 subjects were randomized, and 34 were analyzed. Mean age was 75.4 y (26 males [76.5%] and 8 females [23.5%]). Visual analog scale score for dyspnea (SD) before treatment was 33 (13.9) mm and 42 (17.5) mm in the control and intervention groups, respectively. PASE score before treatment was 78.0 (45.1) and 57.7 (38.0) in the control and intervention groups, respectively. No significant difference in changes in dyspnea severity and PAL was observed between the 2 groups.
CONCLUSIONS: No significant difference was observed for dyspnea and PALs in subjects after blowing air toward their own faces with a small fan for 3 weeks at home. Disease variability and impact of protocol violations were high due to small number of cases. Further studies with a design focused on subject protocol adherence and measurement methods are required to understand impact of air flow on dyspnea and PAL.

OBJECTIVE: Various methods have been proposed to achieve the nearly complete decontamination of the surface of implants affected by peri-implantitis. We investigated the in vitro debridement efficiency of multiple decontamination methods (Gracey curettes [GC], glycine air-polishing [G-Air], erythritol air-polishing [E-Air] and titanium brushes [TiB]) using a novel spectrophotometric ink-model in 3 different bone defect settings (30°, 60°, and 90°).
METHODS: Forty-five dental implants were stained with indelible ink and mounted in resin models, which simulated standardised peri-implantitis defects with different bone defect angulations (30°, 60°, and 90°). After each run of instrumentation, the implants were removed from the resin model, and the ink was dissolved in ethanol (97%). A spectrophotometric analysis was performed to detect colour remnants in order to measure the cumulative uncleaned surface area of the implants. Scanning electron microscopy images were taken to assess micromorphological surface changes.
RESULTS: Generally, the 60° bone defects were the easiest to debride, and the 30° defects were the most difficult (ink absorption peak: 0.26±0.04 for 60° defects; 0.32±0.06 for 30° defects; 0.27±0.04 for 90° defects). The most effective debridement method was TiB, independently of the bone defect type (TiB vs. GC: P<0.0001; TiB vs. G-Air: P=0.0017; TiB vs. GE-Air: P=0.0007). GE-Air appeared to be the least efficient method for biofilm debridement.
CONCLUSIONS: T-brushes seem to be a promising decontamination method compared to the other techniques, whereas G-Air was less aggressive on the implant surface. The use of a spectrophotometric model was shown to be a novel but promising assessment method for in vitro ink studies.

We study the mechanics of mechanoreceptor hairs in response to electro- and acousto-stimuli to expand the theory of tuning within filiform mechano-sensory systems and show the physical, biological and parametric feasibility of electroreception in comparison to aerodynamic sensing. We begin by analysing two well-known mechanosensory systems, the MeD1 spider trichobothria and the cricket cercal hair, offering a systematic appraisal of the physics of mechanosensory hair motion. Then we explore the biologically relevant parameter space of mechanoreceptor hairs by varying each oscillator parameter, thereby extending the theory to general arthropods. In doing so, we readily identify combinations of parameters for which a hair shows an enhanced or distinct response to either electric or aerodynamic stimuli. Overall, we find distinct behaviours in the two systems with novel insight provided through the parameter-space analysis. We show how the parameter space and balance of parameters therein of the resonant spider system are organised to produce a highly tuneable hair system through variation of hair length, whilst the broader parameter space of the non-resonant cricket system responds equally to a wider range of driving frequencies with increased capacity for high temporal resolution. From our analysis, we hypothesise the existence of two distinct types of mechanoreceptive system: the general system where hairs of all lengths are poised to detect both electro- and acousto- stimuli, and a stimuli-specific system where the sensitivity and specificity of the hairs to the different stimuli changes with length.

With healthcare shifting to the outpatient setting, this study examined whether outpatient clinics operating in business occupancy settings were conducting procedures in rooms with ventilation rates above, at, or below thresholds defined in the American National Standards Institute/American Society of Heating, Refrigerating and Air-Conditioning Engineers/American Society for Health Care Engineering Standard 170 for Ventilation in Health Care Facilities and whether lower ventilation rates and building characteristics increase the risk of disease transmission.
Ventilation rates were measured in 105 outpatient clinic rooms categorized by services rendered. Building characteristics were evaluated as determinants of ventilation rates, and risk of disease transmission was estimated using the Gammaitoni-Nucci model.
When compared to Standard 170, 10% of clinic rooms assessed did not meet the minimum requirement for general exam rooms, 39% did not meet the requirement for treatment rooms, 83% did not meet the requirement for aerosol-generating procedures, and 88% did not meet the requirement for procedure rooms or minor surgical procedures.
Lower than standard air changes per hour were observed and could lead to an increased risk of spread of diseases when conducting advanced procedures and evaluating persons of interest for emerging infectious diseases. These findings are pertinent during the SARS-CoV-2 pandemic, as working guidelines are established for the healthcare community.

Typically, the actual volume of the residual limb changes over time. This causes the prosthesis to not fit, and then pain and skin disease. In this study, a prosthetic socket was developed to compensate for the volume change of the residual limb. Using an inflatable air bladder, the proposed socket monitors the pressure in the socket and keeps the pressure distribution uniform and constant while walking. The socket has three air bladders on anterior and posterior tibia areas, a latching type 3-way pneumatic valve and a portable control device. In the paper, the mechanical properties of the air bladder were investigated, and the electromagnetic analysis was performed to design the pneumatic valve. The controller is based on a hysteresis control algorithm with a closed loop, which keeps the pressure in the socket close to the initial set point over a long period of time. In experiments, the proposed prosthesis was tested through the gait simulator that can imitate a human\'s gait cycle. The active volume compensation of the socket was successfully verified during repetitive gait cycle using the weight loads of 50, 70, and 90 kg and the residual limb model with a variety of volumes. It was confirmed that the pressure of the residual limb recovered to the initial state through the active control. The pressure inside the socket had a steady state error of less than 0.75% even if the volume of the residual limb was changed from -7% to +7%.

The lungs have long been considered a desired route for drug delivery but, there is still a lack of strategies to rationally target delivery sites especially in the presence of heterogeneous airway disease. Furthermore, no standardized system has been proposed to rapidly test different ventilation strategies and how they alter the overall and regional deposition pattern in the airways. In this study, a 3D printed symmetric bifurcating tree model mimicking part of the human airway tree was developed that can be used to quantify the regional deposition patterns of different delivery methodologies. The model is constructed in a novel way that allows for repeated measurements of regional deposition using reusable parts. During ventilation, nebulized ~3-micron-sized fluid droplets were delivered into the model. Regional delivery, quantified by precision weighing individual airways, was highly reproducible. A successful strategy to control regional deposition was achieved by combining an inspiratory wave form with a \"breath hold\" pause after each inspiration. Specifically, the second generation of the tree was successfully targeted, and deposition was increased by up to four times in generation 2 when compared to a ventilation without the breath hold (p < 0.0001). Breath hold was also demonstrated to facilitate deposition into blocked regions of the model, which mimic airway closure during an asthma that receive no flow during inhalation. Additionally, visualization experiments demonstrated that in the absence of fluid flow, the deposition of 3-micron water droplets is dominated by gravity, which, to our knowledge, has not been confirmed under standard laboratory conditions.

OBJECTIVE: The aim of this study was to longitudinally evaluate changes in the pharyngeal airway volume in adolescents treated with fixed orthodontic appliances compared to matched untreated adolescents and to assess its impact on airflow resistance.
METHODS: The sample consisted of 16 adolescents (mean start age of 11 years 3 months) who had started and completed treatment at the orthodontic department of the University of Detroit Mercy School of Dental Medicine. This group was compared to a control that consisted of 16 adolescents (mean start age 12 years) who had two CBCTs with no treatment in between for the purpose of regular orthodontic evaluation. Differences in airway volume, length, minimum cross-sectional area, and the average cross-sectional area were calculated.
RESULTS: The results indicated that the airway volume increased by 39% and was a statistically significant change (P<0.05). Regarding the influence on airflow resistance, the change in cross sectional area was significant in the group treated with fixed orthodontic appliances (P<0.03).
CONCLUSIONS: Adolescents treated with fixed orthodontic appliances do experience an increase in airway volume, as well as a decrease in airway resistance to airflow compared to that in normal growth.

Foraging bumblebees are electrically charged. Charge accumulation has been proposed to enable their ability to detect and react to electrical cues. One mechanism suggested for bumblebee electro-sensing is the interaction between external electric fields and electric charges accumulating on fine hairs on the cuticular body. Such hairs exhibit several functional adaptations, for example, thermal insulation, pollen capture and notably, the sensing of air motion such as flow currents or low frequency sound particle velocity. Both air motion and electric fields are ubiquitous in the sensory ecology of terrestrial arthropods, raising the question as to whether cuticular hairs respond to both stimuli. Here, a model-theoretical approach is taken to investigate the capacity of bumblebee filiform hairs as electric sensors and compare it to their response to air motion. We find that oscillating air motion and electric fields generate different mechanical responses, depending on stimulus frequency and body geometry. Further, hair morphology can enhance one sensing mode over the other; specifically, higher surface area favours electric sensitivity. Assuming a maximum stable charge on the hair that is limited only by electric breakdown of air, it is expected that an applied oscillating electric field strength of approximately 300 V m-1 produces comparable mechanical response on the hair as a 35 mm s-1 air flow oscillating at 130 Hz-an air disturbance signal similar to that produced by wingbeats of insects within a few bodylengths of the bumblebee. This analysis reveals that bumblebee filiform hairs can operate as bi-modal sensors, responding to both oscillating electric and air motion stimuli in the context of ecologically relevant scenarios.

The determination of a suitable sensor location on quadrotor drones is a very important issue for chemical reconnaissance platforms because the magnitude and direction of air velocity is different for each location. In this study, we investigated a customized chemical reconnaissance system consisting of a quadrotor drone and a chip-sized chemical sensor for detecting dimethyl-methylphosphonate (DMMP; a Sarin simulant) and investigated the chemical detection properties with respect to the sensor position through indoor experiments and particle image velocimetry (PIV) analysis of the system. The PIV results revealed an area free of vortex-vortex interaction between the drone rotors, where there was distinctly stable and uniform chemical detection of DMMP. The proposed chemical reconnaissance system was found to be realistic for practical application.